Question: If $x \bigtriangledown y = 4x-5y$ and $x \bigtriangleup y = 4y+4$, find $(5 \bigtriangledown 0) \bigtriangleup -5$.
Answer: We don't need to find $5 \bigtriangledown 0$ because $x \bigtriangleup y$ depends only on the right operand. Find $x \bigtriangleup -5$ $ x \bigtriangleup -5 = (4)(-5)+4$ $ \hphantom{x \bigtriangleup -5} = -16$.